Electric welding machine for allmetal spools



July 2, 1935. J. ca. JONES ET AL ELECTRIC WELDING MACHINE FOR ALL METALSPOOLS Filed Aug. 1, 1933 2 Sheets-Sheet 1 woodtiDewe .Hmdlms WKQE 323%Q July 2, 1935. J. G. JONES ET AL. 2,006,459

ELECTRIC WELDING MACHINE FOR ALL METAL SPOOLS Filed Aug. 1, 19,33 2Sheets-Sheet 2 mums CURRENT.

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abbot wa Patented July 2, 1935 UNITED STATES PATENT OFFICE ELECTRICWELDING METAL MACHINE FOR ALL- SPOOLS York Application August 1, 1933,Serial No. 683,155

8 Claims.

The present invention relates to an electric welding machine and moreparticularly to the welding station for an automatic machine to be usedin the manufacture of all-metal photo- 51 graphic spools.

The primary object of the present invention is the provision in anautomatic electric welding machine of an actuating means for moving apair of electrodes back and forth with respect to each other and whichincludes a connecting means having adjustable components so that themovement of the electrodes with respect to each other may be varied.

A further object of the present invention is the provision in anautomatic electric welding machine of a pair of electrodes which maybereciprocated with respect to each other and of movable conductorsforming electrical connections between electrodes and a source ofelectrical energy.

Still another object of the present invention is the provision in anautomatic electric welding machine of a welding circuit which'includesthe secondary of a welding transformer, a pair of electrodes, theflanges and the spool core of a photographic receptacle in contactingposition between the electrodes.

The foregoing and other objects of the invention are embodied in awelding station for an automatic electric welding machine whichcomprises a pair of electrodes slidably mounted within respectivesupports. A rocker means immediately supervises the reciprocation of theelectrodes and a cam means imparts a predetermined motion to theelectrodes through an intermediate connecting means which is adapted tobe adjusted for variations of the reciprocating stroke of theelectrodes. The secondary of the welding transformer is connected to therespective elec- 40 trodes in series by means of a pair of movableconductors which form permanent and low resistance connections betweenthe transformer and the electrodes.

Reference is hereby made to the accompanying drawings, in the severalviews of which, similar reference characters designate similar elementsand in which:

Fig. l is a vertical cross section through the welding station of anautomatic electric welding machine.

Fig. 2 is a fragmentary front elevation of the welding station showingparticularly the connecting means for imparting movement to theelectrodes.

Fig. 3 is a horizontal cross section through the holder for the spoolcore and is taken on the line 3-3 of Fig. 1.

Fig. 4 is a time chart illustrating the relative timing of the cam formoving the electrodes and the cam for controlling energization of thewelding circuit, an oscillagraph of the welding current also beingindicated in timed relation.

Fig. is a fragmentary cross section of an electrode to a larger scale.

In the illustrated embodiment of the invention, the welding stationismounted upon a pair of bed plates l0 and II. A support l2 forms a sleevel3 and is mounted upon bed plate III while a support I4 has a sleeve l5and is mounted upon bed plate H.

A pair of electrodes i6 and I! are mounted to slide within the sleevesI3 and I5 of respective supports l2 and I4. Electrode It has aconducting terminal I! having an enlarged portion I l sliding within abearing sleeve is surrounded by an insulating sleeve 20 which is mountedwithin sleeve I3, while electrode II has a conducting terminal 2| havingan enlarged portion 2| sliding within a bearing sleeve 22 surrounded byan insulating sleeve 23 which is mounted within sleeve l5. A rearbearing 24 and an intermediate bearing 25 support the rear end andintermediate portions of electrode l6, respectively, while a rearbearing 26 and an intermediate bearing 21 support respective rear 30 andintermediate portions of electrode IT.

The conducting terminals l8 and 2| are insulated from the remainder ofelectrodes l6 and H, this construction being only illustrated withrespect to electrode ll. An insulating plug 28, see Fig. 5, is set intoconducting terminal l8 and is provided with a recess 29. A rod 30extends from electrode 16 into an axial hole within plug 28.

The conducting terminal I8 is also resiliently separated from theremainder of the electrode l8 by a coil spring 3| which encircles rod 30and extends into recess 29. A threaded sleeve 32 is screwed ontoelectrode 16 and is locked in desired position thereon by a lock nut 33.A similar threaded sleeve 32 and lock nut 33 are positioned onelectrode, H.

A locating means such as a positioning pin 36 is mounted in the end ofeach conducting terminal I8 and 2|.

An actuating means for moving the electrodes includes a rocker means formoving the electrodes in opposite directions, a cam means having apredetermined motion, and a connecting means for transmitting aproportional part of said pre- 5 determined motion from the cam means tothe rocker means. I 2 l I I The rocker meanspreferably includes a rockshaft 39 which is rotatably mounted in the bed plate .IO and whichsupports a rocker member 48 having arms 4! and 42. A rod 43 is slidablysupported by a sleeve 44, has one end attached to electrode I! by abracket 45, and is pivotally connected at the other end to the arm 4| ofrocker member 48 by a jaw 46 which may be adjusted axially of rod 43 bya pair of nuts 41 threaded onto said rod 43. A jaw 48 is adjustablyclamped to electrode I6 by a bolt 49. A block 50 slidably engages jaw 46and is pivotally connected. to arm 4| of rocker member 40 by a pin whilea block 52 slidably engages jaw 48 and is pivotally connected to arm 42by a pin 53. Upon rotation of' rock shaft 39, electrodes l6 and I! aremoved from the posi- -tion shown in Fig. 1 toward each other and thesleeves 54 and 55' which are mounted within re-- spective supports l2and I4. A circular plate 56 is attached to sleeve 51 which is slidablyand rotatably supported upon the exterior of sleeve 44 and which islocated adjacent sleeve portion 13 of support ii. A plurality of clutchmem bers 58 are positioned in circumferentially spaced apertures inplate 56 and are adapted to support one of the members to be welded,such as a spool flange 59. The plate 56, sleeve 51 and clutch members 58are. duplicated to form a support for members to be welded adjacent tosleeve portion l5 and support l4.

The cam means of the actuating means preferably includes a cam shaft 65which is rotatably' mounted on the machine in any suitable manner, acylindrical cam 6| flxed to cam shaft 60 and provided with a cam slot62, and a plate cam 63, aflixed to shaft 68 and performing a functionlater to be described.

-The connecting means of the actuating means is shown in Fig. 2 of thedrawings and includes a bell crank 64 intermediately pivoted upon ashaft 65 which is supported by a bracket 66 attachedto support I! by aplurality of bolts 61. A cam follower 58 is rotatably mounted upon aspindle 69 which is attached to one end of a bell crank 64by anut whilethe other end of bell crank 64 is provided with an arcuate slot 1 I. Theconnecting means also includes a crank arm I2 afiixed to rock shaft 39by a set screw 13 and includes a link I4 which has oneend pivotallyconnected to the crank arm 12 by a ,bolt and nut I6 and which has theother end adjustably connected to said other end of bell crank 64 withinarcuate slot 'II by means of washers I1 and I8, bolt I9 and nut 86. Thearcuate slot II is curved about the axis of bolt 15 as a center and hasa radius of curvature equal to the distance between the axes of bolts I5and I9. The cam follower 66 is located within cam slot 62 and receives adefinite predetermined motion corresponding to the amplitude and contourof said camslot 62.

Upon the rotation of cam shaft 56, cam 6| is rotated and cam follower 68is givena predetermined motion by the cam slot 62. This predeterminedmotion is the same for any one design of the cylindrical cam and isimparted to bell crank 64. However, the proportion of the saidpredetermined motion which is transmitted by link 14 and crank arm 12 torock shaft 39 depends upon the location of bolt 19 within arcuate slotH. Furthermore, link 14 may be adjusted to various angular positionsabout the axis of bolt I5 without causing any relative motion betweenthe elements of the connecting means or the actuating means.

A holder 8! is mounted upon the machine in any suitable manner and islocated in the position shown in Fig. 1. HolderBI comprisesa pair ofarms 82 and 83 as well as pair of jaws 84 and 85 attached to the ends ofrespective arms 82 and 83. I The jaws 84 and 85 of holder 8| arerecesscd to grip and support. a spool core 86, see

Fig. 3. The ends of jaws 84 and 85 are faced with insulating end strips8! beyond which the ends of core 86 extend a small distance.

The spool flanges 59 are provided with projections 59' according to thedisclosure of Patent #1,754,205 issued to John G. Jones on April 8, 1930and are dished according to the disclosure in our co-pending applicationfor improvements in a Method of welding spools, Serial No. 683,154 fliedon even date herewith. The dishing of flanges 59 and the provision ofprojections 59' thereon prior to the welding operation is disclosed atone end of Fig. 3 while the position and condition of the flange afterthe weldin Operation is shown at the other end of Fig. 3.

When the machine is started, rock shaft 39 will be rotated in aclock-wise direction from the position shown in Fig. l by the action ofsaid cam means andsaid connecting means. As a result rocker member 40will also rotate in a clock-wise direction and the conducting terminalsl8 and 2| of respective electrodes l6 and II will be moved toward eachother. In their travel toward each other terminals l8 and 2| will moveinto abutting relation with respect to the spool flanges 59 held in theclutch members 58 of plates 56. The positioning pins 36 will enter theflanges 59. Further movement of terminals l8 and 2| releases flanges 59from the clutch members 58 but the positioning pins 36 support saidflanges 59 upon the ends of electrode terminals l8 and 2|.

Continued movement of the rock shaft 39 by the cam and the connectingmeans moves the conducting terminals 18 and 2| of the electrodes intothe positions indicated by dotted lines in Fig.

1 with the projections 59 of spool flanges 59 in abutment with the endsof the spool core 86 as shown at the left side of Fig. 3. Additionalmovement of the rock shaft 39, now moves electrodes l6 and I! withrespect to' the conducting terminals I8 and 2! so that coil springs 3|are compressed and so that projections 59' are resiliently pressedagainst the ends of spool core 86 at a pressure corresponding to thetension of said springs 3|.

The electrodes l6 and I1, regardless of the adjusted position of link14, are always returned to the positions shown in Fig. 1. Raising orlowering of the adjustable end of link 14 within arcuate slo t II,merely decreases or increases, respectively, the distances traveled bythe electrodes I6 and' H from this inoperative position of rest.Therefore, if the projections 59 of flanges 59 are not being moved intoabutment with the ends of sired. However, if only one of the conductingterminals I9 or 2| is being moved too far, then the adjustment must beaccomplished by changing the axial position of jaw 49 on electrode I9 orjaw 46 on rod 43.

A welding circuit is'adapted to supply a suitable welding current to theelectrodes and includes a welding transformer and a pair of movableconductors between the leads of the transformer secondary and theelectrodes. The welding transformer has a primary 99 and a secondary 99which has a pair of leads 99 and 9I. A bushing 92 is clamped to theenlarged portion I9 on conducting terminal I9 of electrode I9 while abushing 93 is clamped by a bolt 94 to the enlarged portion 2|onconducting terminal 2i of electrode IT. A stationary bushing 99 isattached to but insulated from the sleeve I 3 of support I2 and astationary bushing 96 is attached to but insulated from sleeve I6 ofsupport I4. The transformer secondary leads 99 and 9| are connected tostationary bushings 95 and 96, respectively. A bowed conductor 91 hasone end journaled in bushing 92 and the other end journaled instationary bushing 95 while a bowed conductor 99 has one end journaledin bushing 93 and the other end J'ournaled in stationary bushing 99.

The journal bearings in bushings 92 and 93 will have a definite travel.upon movement of the conducting terminals I9 and 2I of electrodes I6and I1 and the journal bearings in stationary bushings 95 and 96 arespaced laterally from and opposite an intermediate portion of the pathof the journal bearings in bushings 92 and 93. As a result bowedconductors 91 and 99 will swing about stationary bushings 95 and 99 butthe ends of said-conductors 91 and 98 which are journaled in bushings 92and 93 will move in a straight line with electrodes I6 and I1. However,the resiliency in bowed conductors 91 and 99 will compensate forcurvature in the path through which the ends of conductors 91 and 98would normally move and the distances between the journal hearings inbushings 92 and 95. 93 and 96, may be selected so that such curvature isnot appreciable. This manner of mounting the movable conductors of thewelding circuit prolongs the life of these conductors which must belarge in cross-section to carry the excessive welding currents necessaryfor electric welding and particularly series weld- The weldingtransformer is energized through supply mains 99 of a suitable source ofelectrical energy. The energization of the welding transformer must betimed with respect to the movement of electrodes I6 and I1 and shouldtake place only after the conducting terminals l9 and 2| of saidelectrodes I6 and II have carried the projections 59 on spool flanges 59into abutment with the ends of spool core 96 to complete the weldingcircuit through the transformer secondary 99, wires 99 and 9|, bushings95 and 96, bowed conductors 91 and 98, bushings 92 and 93, andconducting terminals I8 and 2|. Such energization of the weldingtransformer is governed by a control circuit which includes a switch operated by the cam means in timed relation to the movement of electrodesI6 and IT.

The cross-section of the spool core 96 is materially reduced by theslots I29 and I39 which are generally provided in the cores ofphotographic spools. As a result the welding current may be so large asto cause excessive heating and distortion of the spool core 96 adjacentthe slots I29 and I39. Consequently the jaws 94 and 99 of the holder maybe composed of conducting material such as copper, so that additionalconducting area is provided for the welding current which must otherwisepass through spool core 99.

The control circuit includes the secondary I99 of a transformer whichhas its primary I9I connected in series with one of the supply mains 99.A pair of grid controlled rectifiers I92 and I99 of the hot cathode gasfilled type are connected in inverse relation across the leads I94 andI99 of the series transformer secondary I99. The rectifier I92 has acathode I99 connected to lead I99 and an anode I91 connected to lead I94while rectifierl93 has a cathode I99 connected to lead I94 and an anodeI99 connected to lead I99. A grid transformer has a primary winding III,a secondary winding I I I which is connected at one end to the grid II2of rectifier I92 and at the other end to lead I94, and another secondarywinding H3 which is connected across the grid II4 of rectifier I93 andlead I94, ends of opposite polarity of the windings III and H3 beingconnected to the respective grids H2 and 4. A filament transformer UShas one side connected through a resistor II6 to one side of the primaryII9 of the grid transformer and has an intermediate tap II I connectedto the other side of primary H9 of the grid transformer. The controlcircuit also includes a switch which may be composed of a pair ofcontacts I I9 and I I9. Contact I I9 is connected by a wire I29 to oneside of filament transformer II5 while contact H9 is connected by a wireI2I to one side of the primary II9 of the grid transformer. Electricalenergy is supplied to the two sides of filament transformer H5 of avoltage preferably equal to that across the supply mains 99.

The switch of the control circuit is operated by the plate cam 63 of thecam means in timed relation to the movement of the electrodes I6 and I1.A yoke I22 rotatably supports a roller I29 and has a stem I24 whichslides within a bracket I25 affixed to the machine. A coil spring I29encircles stem I24 between a collar I2'I fastened thereto and a washerI29 resting on bracket I29. A rod I29 is attached to yoke I22 andcarries contact I I9 of the switch for the control circuit. The coilspring I26 maintains roller I23 against the edge of plate cam 63 andcontact H9 is raised to closed position and lowered to open position bythe movements of yoke I22 which correspond to the outline of cam 63.

Upon rotation of plate cam 63, the yoke I22 is raised by spring I26 andcontacts H9 and H9 .make contact. The grid transformer is energized andan alternating potential is impressed upon the grids I I2 and H4 ofrectifiers I92 and I93. The potential on the grids of the gas filledrectifiers will draw an are between the anode and cathode in one tubeduring the first half cycle of the alternating current supply andbetween the anode and cathode in the other tube during the next halfcycle of the alternating current supply. In effect, the secondary I 99of the series transformer is short-circuited so that the impedance ofthe supply circuit is materially reduced and the current in the primary99 of the welding transformer is increased. When the contacts H9 and H9are separated again the alternating potential between the cathodes andanodes of rectifiers I92 and I93 will be reduced to zero during the nextcycle so that the rectifiers will cease to arc, the impedance of theseries transformer will increase and the current passing through primary88 or the welding transformer will be reduced.

The cylindrical cam 8| has a contour which is represented by the lowesttime chart in Fig. 4 and the'plate cam 53 has an outline represented bythe middle time chart of Fig. 4. Cams BI and 83 are both mounted upon acommon cam shaft 60 and their relative timing is illustrated in thesetwo charts of Fig. 4. The relation of cams 6| and 63 is such that afterthe conducting terminals l8 and 2| of electrodes l6 and I! have carriedthe projectors 59 of flanges 59 into abutment with the ends of core 86,the contact points 8 and H9 are closed and the welding current flows asindicated in the topmost chart of Fig. 4.

The welding current melts the projectors 59 on the flanges 59 and theadjacent portions of the spool core 86 so that a plurality of welds areformed between the core 86 and the flanges 59. The resilient pressureson the conducting terminals l8 and 2| cause compression of the moltenportions and move the flanges 59 into abutment with the ends of core 86.The cam. 53 then sepa rates contacts l l8 and H9 so that the weldingcurrent is cut off. The flanges 59 now cool and assume a plane surfaceformation. The clearance between the flanges 59 and the insulating endstrips 81 is very small, being about 0.003 of an inch, so that theflanges cannot buckle in the opposite direction, but if exhibiting sucha tendency will be flattened out against end strips 81, as indicated bydotted lines at the right side of Fig. 3.

The conducting terminals l8 and 2| of electrodes l6 and I! remain inwelding position, as represented by the higher horizontal line of thecylindrical cam chart, until the welds have cooled sufliciently,whereupon the electrodes are retracted leaving the finished spoolbetween the jaws 84 and of holder 8|.-

Since many modifications of the present invention may be made withoutdeparting from the spirit thereof, the present disclosure is to beconstrued in an illustrative and not in a limiting sense.

Having now particularly described our invention what we claim as new andwhat we desire to secure by Letters Patent of the United States 1. In amachine for welding spool flanges to a core, the combination with aholder adapted to support a core, a pair of supports, and a pair ofelectrodes each movable in its respective support and each adapted tocarry a spool flange, of a single actuating means for said electrodes,including a rocker means connected to each of said electrodes and formoving the same in opposite directions, including a single cam meanshaving a predetermined motion, and including a connecting means fortransmitting a proportional part of said predetermined motion from saidcam means to said rocker means.

2. In a machine for welding spool flanges to a core, the combinationwith a holder adapted to support a core, a pair of supports, and a pairof electrodes each movable in its respective support and each adapted tocarry a spool flange, of a single actuating means for said electrodes,including a rocker means connected to each of said electrodes and formoving the same in opposite directions, including a single cam meanshaving a predetermined motion, and including a connecting means havingan adjustable link for varying the proportion of said predeterminedmotion transmitted from said cam means to said rocker means,

3. In a machine for welding spool flanges to a core, the combinationwith a. holder adapted to support a core, a. pair of supports, and a.pair of electrodes each movable in its respective support and eachadapted to carry a spool flange, o! a single actuating means for saidelectrodes, including a rocker means connected to each of saidelectrodes and for moving the same in opposite directions, including asingle cam means having a predetermined motion, and including aconnecting means for transmitting aproportional part of saidpredetermined motion from said cam means to said rocker means, saidconnecting means having a movable link for transmitting motion and whichis adjustable to various angular positions to vary the proportions ofthe transmitted motion.

4. In a machine for welding spool flanges to a core, the combinationwith a holder adapted to support a core, a pair of supports, and a pairof electrodes each movable in its respective support, and each adaptedto carry a spool flange, of a single actuating means for saidelectrodes, including a rocker means having adjustable connections toeach of said electrodes and for moving the same in opposite directions,including a single cam means having a predetermined motion, andincluding a connecting means for transmitting motion and a proportionalpart of said predetermined motion from said cam means to said rockermeans.

5. In a machine for welding spool flanges to a core, the combinationwith a holder adapted to support a core, a pair of supports, and anelectrode movable in each support and adapted to carry flanges intoabutting position with respect to the ends of said core, of a rodattached to one electrode and movable in said support, a rocker membercentrally pivoted and having two arms, a pivotal connection between saidrod and one arm of said rockermember, and a second pivotal connectionbetween said other electrode and the other arm of said rocker member,both pivotal connections being adjustable respectively along said rodand said other electrode.

6. In an electric welding'machine, the combination with a pair ofsupports, a pair of electrodes each movably mounted in its respectivesupport, a bushing attached to each electrode, and an actuating meansfor imparting to said electrodes 2. definite stroke in oppositedirections, of 9. Stationary bushing on each support in spaced relationto and opposite the center of the path travelled by the bushing on eachelectrode a. welding transformer having a. pair of secondary leadsconnected to respective stationary bushings, and a pairof arcuateconductors, each having one end journaled in the bushing on said supportand the other end journaled in the bushing on said electrodes.

'7. In a machine for electrically welding spool flanges to a coreprovided with a central longitudinal slot, the combination with a holderadapted to support the core and including a conductor which is adaptedelectrically to contact said core adjacent the ends thereof andelectrically to bridge the slot in said core, and a pair of electrodesmovably mounted and adapted in operative position to maintain theflanges against the ends of said core, of a series welding circuitincluding said electrodes, adapted to include said flanges in abutmentwith the ends of said core, and inmaintain the flanges against the endsof said core in said holder, 01' a series welding circuit including saidelectrodes, adapted to include said flanges in abutment with the ends ofsaid core, and including said conducting jaw in parallel across theslotted portion of said core.

JOHN G. JONES. HAYWOOD G. DEWEY.

